not sure if this will help you seems like a simple diy alternative, http://www.llamma.com/xbox/Repairs/Reading_Xbox_Hdd_key.htm
Thats the eeprom for settings like hddkey etc, not the chip that stores the bios (which if he was saying nand, is what id assume he was talking about)
ahh okies just had a quick look over it, arnt all the xbox bios's the same(assuming its the same region and revision). could he not just try find an already dumped bios, idk maybe he wants to jtag his xbox original lol, anyways OP if your just looking to chip your original Xbox I've never had a problem with softmods and they have pretty much all the same features as actual chipped consoles
The 29 wire chips were TSOP replacements so I suppose you could use the points they used to program the thing. Maybe. Be easier to remove it and program it properly.